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Re: Meta decorator with parameters, defined in explicit functions

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On Mon, Jul 4, 2016 at 9:25 AM, Lawrence D’Oliveiro
<lawrencedo99@gmail.com> wrote:
> On Monday, July 4, 2016 at 10:39:30 AM UTC+12, Ian wrote:
>> Sorry, but you're the one who doesn't seem to get it. Because it's a
>> decorator, "your" function is replacing the caller's function in the
>> caller's namespace.
>
> No it is not. The replacement happens here:
>
>         def generated_decorator(func) :
>             return \
>                 decorator(func, *args, **kwargs)
>         #end generated_decorator
>
> As you can see, the function being called, “decorator”, is supplied by the caller. The function being decorated, “func”, is supplied by the caller (along with the additional *args and **kwargs). And the returned function is returned *as-is*, so whatever docstring was assigned by the caller is *NOT* “clobbered”.
>
> Once again, the only docstrings I am setting are the ones for functions that *I* generate.
>
> Do you understand that yet?

Yes, in a technical sense, you are correct. It's also technically
correct to say that str.upper() doesn't convert its argument to
uppercase - it constructs a completely new string of all uppercase
letters. But in normal usage, people expect "x = x.upper()" to return
*the same string, uppercased*. In the same way, people expect "f =
deco(f)" to return *the same function, decorated*. Technically it's
generally going to be a new function, because functions are immutable
(more-or-less), but it should broadly be the same function.

def require_login(f):
    def modified(*a, **kw):
        if not logged_in:
            return "You must be logged in to do this."
        return f(*a, **kw)
    return modified

@require_login
def fire_ze_missiles():
    raise Exhausted

@require_login
def reboot_server(server):
    """Reboot the specified server"""
    server.send_command("sudo reboot")

Tell me, should the docstring for reboot_server be "Reboot the
specified server", or not? If not, why not?

ChrisA

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Meta decorator with parameters, defined in explicit functions Ben Finney <ben+python@benfinney.id.au> - 2016-06-28 15:02 +1000
  Re: Meta decorator with parameters, defined in explicit functions Paul Rubin <no.email@nospam.invalid> - 2016-06-27 23:08 -0700
  Re: Meta decorator with parameters, defined in explicit functions Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-06-28 18:39 +1000
  Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-06-29 19:43 -0700
    Re: Meta decorator with parameters, defined in explicit functions Steven D'Aprano <steve@pearwood.info> - 2016-06-30 13:49 +1000
    Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Peter Otten <__peter__@web.de> - 2016-06-30 09:25 +0200
      Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-06-30 00:43 -0700
        Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-06-30 18:00 +1000
        Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Peter Otten <__peter__@web.de> - 2016-06-30 10:41 +0200
    Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions dieter <dieter@handshake.de> - 2016-07-01 09:04 +0200
      Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-07-01 21:25 +0100
        Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Ben Finney <ben+python@benfinney.id.au> - 2016-07-02 11:52 +1000
        Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions dieter <dieter@handshake.de> - 2016-07-02 08:57 +0200
        Re: Fear and suspicion of lambdas, was Re: Meta decorator with parameters, defined in explicit functions Ben Finney <ben+python@benfinney.id.au> - 2016-07-02 18:00 +1000
  Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-06-29 19:50 -0700
  Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-01 15:08 -0700
    Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-01 23:09 -0600
      Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-01 23:40 -0700
        Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-02 22:48 -0600
          Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-02 22:37 -0700
            Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-03 05:52 -0600
              Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-03 14:17 -0700
                Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-03 16:38 -0600
                Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-03 16:25 -0700
                Re: Meta decorator with parameters, defined in explicit functions Chris Angelico <rosuav@gmail.com> - 2016-07-04 09:39 +1000
                Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-03 16:59 -0700
                Re: Meta decorator with parameters, defined in explicit functions Chris Angelico <rosuav@gmail.com> - 2016-07-04 10:06 +1000
                Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-03 17:23 -0700
                Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-03 18:01 -0600
                Re: Meta decorator with parameters, defined in explicit functions Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-07-03 17:06 -0700
                Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-03 18:20 -0600
    Re: Meta decorator with parameters, defined in explicit functions Ben Finney <ben+python@benfinney.id.au> - 2016-07-02 15:32 +1000
    Re: Meta decorator with parameters, defined in explicit functions Ian Kelly <ian.g.kelly@gmail.com> - 2016-07-01 23:53 -0600

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